Grease gun



H. KREIDEL Jan. 5, 1932.

GREASE-GUN Filed April 11. 1928 lidera-.rented dan, 5, 1932 EAN SKREDEL, 0K4 WESBAIDEN, GERMANY GREASE GUN Application led April 1l.,1928, Serial No.

The present invention relates to a lubri eating gun having a suction andpressure piston adapted to be actuated by hand, the front portion of thegun being formed as ahigh pressure pump mechanism of which `the springactuated Working and sliding cylinder guided in the bottom of the gunforms a coinmon outflow passage for the lubricant and in which the highpressure pump mechanism automatically comes into operation as soon as ahigher resistance is opposed to the outflow ofI the lubricant and theoutflow nozzle must be pressed more strongly upon the point to belubricated, the entire lubricating gun now sliding forwardly on theworking and sliding cylinder and the ejection pistonof the high pressurepump mechanism enters the cylinder. The lubricating gun maybe used as anordinary lubricating gun and as a high pressure lubricating gun. ln theiirst method oi operation the complete charge of lubricant can beejected successively in small quantities or also at one operation bymeans of the suction and pressure piston. ln the second method ofoperation, however, it is only possible to edect the ejection inseparate quantities, under high pressure, which correspond to the amountby which the ejection piston .or the high pressure pump mechanismpenetrates into the Working and sliding cylinder is preferablyconstructed Without valves so that by means thereof, when withdrawingthe suction and pressure piston provided in the gun cylinder, thelubricant is also drawn from a supply container, the lubricating gunbeing thus capable oibeing lilled in a. simple manner. The Working andsliding cylinder and the ejection piston of the high pressure pumpmechanism are under the action ci a single spring which forces themaxially apart, this spring holding both the cylinder head against thebottom of the gun, and also pressing the perforated supporting plate orthe supporting bar of the ejection piston on a shoulder or the guncylinder in a manner as to be detachable and removable. The packing ofthe Working and sliding .cylinder in the bottom of the gun is edected bymeans of a packing disc tted over and bearing against' the latter, whichdisc is alternately exposed to the action aeazea, alla in Germany Marcha, 192e.

of the spring of the high pressure pump mechanism and the pressure ofthe lubricant. The accompanying drawings show an example of constructionin accordance with the invention in longitudinal section,.in fourdifferent positions.

Figure l shows the lubricating gun in the position of rest, completelyempty and with a protecting cap screwed over the Working and slidingcylinder and the nozzle.

Figure 2 shows the lubricating gun With the nozzle inserted in thesupply of lubricant, Whilst the gun suction and pressure piston is drawnback and consequently has effected the :Filling of the gun. y

Figure 3 shows the lubricating gun When lubricating a ball bearing Whenno Jfriction is opposed, and Figure Ll shows the high pressure pumpmechanism in operation for overcoming a resistance which is opposed tothe outdow of the lubricant when lubricating a sliding bearing.

a indicates the gun cylinder for the receptionof the lubricant andprovided with a bot.- tom b and a cover c. By means or a depressionformed in the cylinder there is obtained an inwardly directed projectionor shoulder d. Above this is located the suction and pressure piston eof the gun, of Which the piston rod f is passed through the cover c andoutside is provided with a suitable hand-piece g. This suction andpressure piston e consists of tivo leather cups having the bottomsthereof pressed against one another or together by l means of a springe1 bearing against a disc f1 secured to the end of the piston rod.

ln the front portion of the gun cylinder a there l is mounted the highpressure pump mechanism. This consists of ther valveless working andsliding cylinder it and the ejection piston t" between Which is locatedthe compressible spring 7a which moves ath-em axially apart. The Workingand slidirg cylinder 7l, is guided in the strengthen@dY portion of thegun bottom b and is provided with a separate .nozzle l for applicationto the point to be lubricated. lnstead of the nozzle shown any othersuitable nozzle may be used.. @n

the Worlring and sliding cylinder i, there is.

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fitted a packing disc m el leather or the like which tightly surroundsit and bears loosely against the gun bottom b. The strengthened head71,1 of the Working and sliding cylinder also bears against the gunbottom or the packing disc 'mplaced 'thereon and against the somewhatenlarged end thereof bears the compressible spreading spring ln the headof the Working and sliding cylinder L is secured a packing disc n oi'leather or the like which serves for packing the ejection pistonrelatively to the internal space oli' 'the 'working and slidingcylinder. The ejection piston t is secured to an annular disc 0 providedwith passages 01, which disc 0 is constantly pressed against thc innerrib or shoulder [Z of' the gun cylinder a. The gun bottom is providedwith an outwardly eX- tending screwed extension b1 on which there may bescrewed, when the lubricating gun is not in use, a cap p for protectingthe projecting part of the Working and sliding cylinder and the nozzlethereof. When the gun is to be used 'the cap is removed. When it isdesired to fill the lubricating gun with lubricant the nozzle Zis dippedinto the supply oit lubricant and the suction and pressure piston e isdrawn back in the direction of the arrow. (Figure 2.) is this can onlybe moved as far as the rib or shoulder d air is contained in the irontportion of the lubricating gun cylinder, containing the high pressurepump mechanism, before the lubricating gun is used for the lirst time7which air must be ejected by moving the suction and pressure piston toand fro a number of times. j

When all the air has been removed 'then on pulling back the suction andpressure piston lubricant is drawn in thus llorvingthrough the nozzle Zand the Working and sliding cylinder h and past the ejection piston iand finally through the openings o1 in the annular disc o to below thesuction and pressure piston and filling the entire free space of the guncylinderk a. li it is now desired to operate upon a point to belubricated with the lubrieating gun which .is non7 ready for use andwhich point does not oppose any resistance to the lubricant, as is forexample the case when lubricating and filling ball bearings, (Figure 3)and annular bearings or when filling lubricant containers of dillerenttypes7 as also when simply ejecting the lubricating material, as is thecase with the usual lubrieating gun, slight pressure on the hand-piece gof the suction and pressure piston e, in the directicn of the arrow(Figure 3), suffices to cause the lubricant to flow out and flow intothe point to be lubricated or into the container-in question.

As soon as any considerable re istance is ed to the lubricant at thepoint of leavnozzle, as is itor example the cn f eating sliding bearings(Fix ure a higher pressure must be exerted on the hand-piece g of thesuction and pressure piston e. By means of the increased pressure thusexerted the lubricant is compressed in the gun cylinder and as soon` asthe pressure exceeds the tension of the spring It the Whole gun movesover the Working and sliding cylinder It of the high pressure pumpmechanism somewhat forwardly and the ejection piston thereof enters thecylinder ll. A portion olf the lubricant contents olf the cylindercorresponding with the depth of penetration of the piston?,l into thecylinder it is thus expelled or ejected under a high pressure. llfnishigh pressure corresponds with the dili'erential ratio of the twopistons e and z' and overcomes the resistances which occur at the outletrom the nozzle L vl/hen pressing the nozzle Z against the point to belubricated a tight joint must be formed between the tWo parts which canbe obtained in a suitable manner for example by suitable construction ofthe parts bearing upon one another' and the surfaces thereof as also bya suitable application pressure1 lThis tight oint, Which when pressingthe lubricatin gun downwardly prevents the lubricant from escapinglaterally also prevents during the return movement of the lubricatinggun or' atmospheric air being drawn in as long as the nozzle remainsseated on the lubricating hole. Consequently there is formed in theWorking and sliding cylinder la Whilst the ejection piston i moves outof it under the action of the expanding spring it, a vacuum by means ofwhich lubricant is drawn from the supply contained in the gun cylinder aat 'the moment at Whichithe free end of the ejection piston z' moves outof the working and sliding cylinder la. During the return movement ofthe lubricating gun on the Working and sliding cylinder L the nozzle Zis held pressed against the pointto be lubricated by the action of thecompressed spring is. lhe suction of lubricant into the Working andsliding cylinder it from the supply contained in the gun cylinder duringthe relieving from pressure of the device is supported by the pressurev'of the suction and pressure piston e which is under the direct actionof the hand and exerted directly on the lubricant before i and after thetensioning of the spring 75.

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pump mechanism can be moved from the front out of the gun cylinder.

I claim as my invention:

l. In a lubricating gun ofthe class described, a low pressure cylinderforming a container for lubricant, a piston reciprocable in saidcylinder and making an air tight and lubricant tight seal therewith whenmoved in both directions, a high pressure cylinder 30 supplied from saidlow pressure cylinder, a A piston for discharging lubricant from saidhigh pressure cylinder, means for connecting said high pressure cylinderin open communication with a part requiring lubrication, and a handlefor moving said low pressure piston in one direction to cause said gunto discharge lubricant and for moving said loW pressure piston in asecond direction to rell said gun with a new charge of lubricant 2othrough the high pressure cylinder.

2. In lubricating apparatus of the class described, a low pressurecylinder forming a lubricant reservoir, a low pressure pistonreciprocable in said cylinder, said low pressure piston includingreversed cup leathers for eii'ecting an air and lubricant tight sealbetween said piston and cylinder when said piston is moved in eitherdirection, a high pressure cylinder in communication with said "i0 lowpressure cylinder, a piston for said high pressure cylinder, a nozzleattached to said high pressure cylinder-and providing an open outletpassageway therefor, and a handle for reciprocating the lowpressurepiston to cause discharge of lubricant under low pressure whenmoved in one direction and to suck in lubricant through the highpressure cylinder into the low pressure cylinder when moved in the otherdirection. v

ec 3. In a lubricating gun of the class described, a low pressurecylinder ormingra container for lubricant, a piston reciprocable in saidcylinder and making an air-tight and lubricant-tight seal therewith whenmoved in either direction, a high pressure cylinder in-'aXial alignmenttherewith and supplied from said low pressure cylinder, a piston fordischarging lubricant from said high pressure cylinder, means forconnecting said high pressure cylinder in open communication with a partrequiring lubrication, and a handle for moving said low pressure pistonin one direction to cause said gun to discharge lubricant and for movingsaid low pressure piston in an opposite direction to re-fill said gunwith a new charge of lubricant through the high pressure cylinder.

In witness whereof I have hereunto set my hand.

G0 HANS KREIDEL.

